"I've always wanted to do a little more than just to play tennis," Federer, who was on his first official field trip as a UNICEF Goodwill Ambassador, said after meeting tsunami-affected children.
"I was in Maldives only two weeks before the tsunami hit, you know, so maybe in a way I was lucky as well, which is why I have such a strong bond and I want to help."
The Dec. 26, 2004 tsunami, generated by a massive earthquake off Indonesia, killed more than 230,000 people in a dozen nations on the rim of the Indian Ocean. Tamil Nadu suffered India's largest toll with 8,000 dead.
"I couldn't believe how big the devastation was," said the nine-times grand slam champion, who has his own foundation supporting disadvantaged children in South Africa.
"That for me was very hard, especially as a person travelling a lot, being to places like Maldives and Indonesia, I feel very attached to them."
The Swiss said he was in Dubai at the time of the disaster.
"I was seeing it on TV. It was a very emotional experience for me as well," he said.
"It has been a tragedy for all of us. That's why I'm here today to show my respect to lives that have been lost and I hope we can help the children.
"Sport is such an emotional thing. We have a lot of fans around the world. When an athlete gets involved in something like this, it raises a lot of awareness. You can help many, many people."